NFL scouts are zeroing in on prime candidates at the Senior Bowl. Not in attendance is Alabama QB A.J. McCarron, who told AL.com that he is resting his body. However, early entry and possible No. 1 draft pick Jadeveon Clowney did show up and interacted with team representatives, including Houston Texans’ coach Bill O’Brien.

On the third day of the event, Optimum Scouting reports the “winners” of the day for the north team were RB Charles Sims, WR Josh Huff, OT Jack Mewhort, DT Aaron Donald, LB Chris Borland and CB Pierre Desir.

Quarterbacks

-- It was clear that Virginia Tech’s Logan Thomas outclassed the other quarterbacks in terms of arm talent and accuracy. However, his lack of polish in areas like footwork and progression timing became more evident as the practice continued. Two interceptions partially spoiled his day, but Thomas drove a variety of intermediate and deep passes with confidence, back end velocity and consistent placement on the receiver’s numbers.

-- The next best quarterback, Tajh Boyd started the day off poorly, misfiring and lacking the confidence to pull the trigger with proper timing on downfield throws. Boyd has arm strength deficiencies and that was obvious throughout the session. When attempting throws downfield and vertically, there’s a noticeable difference in finishing velocity and a looping trajectory. Underneath and in the three-step pass game, however, Boyd is comfortable and in rhythm. He’s got an adjustable delivery but needs to further improve his base width, weight transfer and release mechanics to execute all of the throws at the next level.

-- Miami quarterback Stephen Morris struggled and could be best described as a loose cannon. The positives to his practice session include his live arm, along with willingness to throw back shoulder and attack tight windows during 1-on-1’s and redzone drills. Nevertheless, his arm talent makes up for remarkably inconsistent setup and release mechanics. At times over-striding and other times unable to get on top of his delivery, Morris threw the most incompletions with 14 misfires. He routinely stared down the primary receiver in his 7-on-7 passing opportunities.

Running Backs

-- Charles Sims continued to excel as a pass catcher, showing the soft hands and radius to extend and adjust in the flat areas. He’s well prepared to handle third down duties as a pass protector as well, but needs to keep his feet moving to absorb and control his opponent with more effectiveness. Overall he was the best in blitz pickup drills and continues to impress with his smooth running style.

Wide Receivers/Tight Ends

-- Of the receivers, Josh Huff of Oregon had the best day of the bunch. While he still struggles a bit with press coverage, he is physical down the field, especially in the red zone fade. He finished at the catch point very well today, and used his hands to separate (legally) against all types of cornerbacks.

-- Battling for the top receiver of the day was Wyoming’s Robert Herron. He’s quick throughout his routes, flips his head around quickly to the quarterback, and is smooth at the top of his route in attacking the ball. He also gets of press remarkably well for a small receiver, even though he likely won’t be asked to do that much in the NFL as a slot receiver.

-- Jared Abbrederis of Wisconsin is such a technician as a route runner, and he works so well to get cornerbacks outside the framework of their body as he sets up deep breaking routes. He seems focused throughout his routes on every play. Throughout the week, he’s been arguably the top receiver in attendance at the Senior Bowl.

-- Shaquille Evans of UCLA has the size and athleticism to attack vertically and separate with that body control. But his routes are very rounded at this point, and despite beating defenders at time throughout the day, his routes won’t be suitable for the NFL level in terms of getting his own separation.

-- Tight end CJ Fiedorowicz of Iowa was clearly the best of the bunch, and his size, fluidity as a receiver in the short area, and body positioning in both pass catching and run blocking sets was impressive. He’s a polished tight end who may not have the elite athleticism to go in the Top 50, but he looks the part of a long-term tight end in the NFL.

Offensive Line

-- Jack Mewhort has been working at guard and tackle this week and many believe he can start at both positions in the NFL. He had a really impressive day as he consistently displayed a heavy anchor, proper slide technique, and efficient hand usage against opponents. Even better was his determination to finish during the last padded practice. He worked Ra'Shede Hageman to the ground during one-on-ones and flattened North Carolina DE Kareem Martin in team.

-- Utah State center Tyler Larsen had a strong showing during one-on-ones, particularly against the (likely) biggest winner of the week, Aaron Donald. He was exceptional in keeping Donald at bay, consistently fighting for leverage through his block and sliding cleanly to mirror Donald’s counters. While his arm length is a concern (30.5 inches), Larsen wins by battling underneath the reach of bigger interior linemen and constantly moving his hands.

-- Someone must have had a pep talk with Seantrel Henderson because he came to play Wednesday. Before practice, scouts were overheard ranting about how the Miami tackle “has looked big on the field but hasn’t played big on the field” during Senior Bowl practices. He flashed dominance (as he does on film) during the team session, easily washing out the contain end to open up a huge hole for a Charles Sims touchdown. His footwork also improved as he took to coaching well. If he wants it, there are teams that will be willing to teach him to be great.

Defensive Line

-- Aaron Donald was once again absolutely dominant for the third day in a row. In one-on-one drills, the Pitt product was unblockable (and it wasn’t close) with the exception of his matchups with Tyler Larson and Jack Mewhort. His first step is exceptional and he’s a master of the leverage game, attacking opponents’ shells from the ground up. Baylor’s Cyril Richardson really struggled to react and match foot speed against Donald’s swim move a number of occasions.

-- Minnesota defensive tackle Ra’Shede Hageman is massive but he’s not as limber as teams might prefer. From drills to team sessions, Hageman lacked explosion and had issues finishing the entire day. He was noticeably frustrated during one-on-ones as he struggled to shed blocks and was eventually pancaked badly by Mewhort toward the end of the session.

Linebackers

-- Chris Borland excelled again in his diagnosis of plays, composed read steps and instincts. Borland fits in the run game better than any of the backers here, has the hip snap to meet blockers in the hole and stay balanced to disengage for the play. During team drills, he even showcased cover skills by baiting Logan Thomas into a interception on a late shallow cross throw over the middle of the field. Borland will be a riser for us at Optimum Scouting after this week.

-- Another linebacker who showed out today was Iowa’s Christian Kirksey. Instinctive and fast flowing to the football, Kirksey exhibited the quickness and transition speed to more than adequately cover the seams as a weakside linebacker. In addition to movement skills, he flashed multiple times as a blitzer during blocking drills against the running backs and tight ends.